This invention relates to an improvement of the fuses disclosed in U.S. Pat. No. 3,413,585; 11/26/68 to Frederick J. Kozacka for ELECTRIC CARTRIDGE FUSE HAVING OFF CENTER FUSIBLE ELEMENTS. That patent solves the problem of increasing the ratio of axial to radial heat flow in a fuse having a relatively long casing and a relatively short fusible element by arranging the fusible element off-center, i.e. relatively close to one of the caps of the fuse. This increases the axial heat flow to the cap or terminal closest to the fusible element and by so doing limits the temperature prevailing near the center of the casing of the fuse.
In U.S. Pat. No. 3,413,585 the fusible elements is directly connected to the knife blade contacts, e.g. by spot welding. This results in a relatively unflexible structure. The contrary of that is required, i.e. a relatively flexible structure, because the relatively thin and fragile fusible element is readily deformed by external forces, e.g. by torsional forces, transmitted to it by movements of the knife blade contact relative to the fusible element.
It is therefore, one object of the invention to provide fuses of the above kind, i.e. having off-center fusible elements, that increase the ratio of axial to radial heat flow and thus limit the peak temperature in the region of the center of the casing, or limit the temperature prevailing at this point.
Fuses having knife blade contacts that project from the outside of the casing through the ends surfaces of the terminal caps to the ends of an off-center fusible element, or to the ends of a plurality of off-center fusible elements, require a relatively large amount of blade contact material, i.e. of copper. It is another object of this invention to reduce the amount of blade contact material without any significant increase of the voltage drop across the fuse.
These and other objects of the invention will become more apparent as the present specification proceeds.